Knowledge on asymptomatic malaria and Plasmodium vivax treatment in a hard-to-reach Amazonian population: a mixed-methods exploratory study

Introduction

In 2022, 72% of malaria cases in the Americas were attributable to Plasmodium vivax (Pv). As transmission declines, malaria transmission mostly concentrates in hard-to-reach populations. An example of such a population are the persons involved in artisanal and small-scale gold mining (ASGM), often working informally in remote and forested areas, with difficult access to healthcare and prevention and a high regional mobility.

CUREMA is a complex intervention aiming at accelerating malaria elimination in ASGM communities of the Guiana Shield (GS). It relies on (i) health education activities, (ii) targeted treatment of asymptomatic persons considered at risk of Pv carriage, (iii) delivery of self-test and self-treatment kits. For successful interventions, community acceptability is essential and closely linked to their knowledge and representations of the disease. The objective of this work is to explore the knowledge, experiences, and representation of the target population of CUREMA intervention.

Methods

We analyse data of pre-intervention surveys using a mixed-methods approach. Data collection occurred in the second semester of 2022 in ASGM rear-bases located in Brazil and Suriname. A qualitative survey, performed with an ethnographic approach and based on participants observation, semi-structured interviews and informal Discussions. Quantitative data was collected through a cross-sectional survey, including a questionnaire on knowledge, attitudes, and practices regarding malaria.

Results

In the qualitative survey, 23 individual and 14 group interviews were conducted, along with 38 informal conversations; 539 participants were enrolled in the quantitative survey, mostly men (73.5%), with a median age of 38 years. The role of mosquitoes as vector of the disease was well known by participants, even if understanding the cause of the disease (microorganism, “virus da malária”) was shared by only a fraction. Most of them recognized different types of malaria, characterized by different severity and treatments; some were able to name “falci” and “vivax” as the main ones.

Most of participants mentioned the existence of asymptomatic carriage of malaria that can trigger recurrences (malaria “incubada”), especially after exposure to specific foods and beverages. This phenomenon was considered to be associated to improper treatment and to occur in any type of malaria. The study population had poor knowledge and limited experience of Pv treatments (chloroquine and primaquine).

Discussion

The ASGM community has a widespread knowledge of malaria based on individual and collective experience of the disease, including on asymptomatic carriage and recurrence risk. However, knowledge on Pv radical cure for relapse prevention is poor and need to be improved. Knowledge influences adherence to interventions. Disease understanding plays a key role in individual decision-making. It is crucial to develop context-specific interventions, aware of local culture and issues, to improve acceptability and accessibility of care. These results have been used for designing CUREMA project educational tools, and may be useful for those involved in eliminating malaria in the Amazon, by improving the acceptability and effectiveness of malaria elimination efforts.